Problem: Subtract. $\dfrac{9}{8} - \dfrac{5}{12} = $
Explanation: Before we can subtract our fractions, they need to have the same denominator. $\dfrac{9}{8}$ $\dfrac{5}{12}$ $\dfrac{9}{8}-\dfrac{5}{12}$ Let's look at the multiples of each denominator and see which multiples they have in common. Denominator Multiples ${8}$ $8, 16, \underline{24}$ $12}$ $12, \underline{24}, 36$ The least common denominator is ${24}$. Let's use multiplication to make each fraction have a denominator of $24$. ${\dfrac{9}{8}}=\dfrac{{9} \times {3}}{{8} \times {3}} = {\dfrac{27}{24}}$ $\dfrac{5}{12}}=\dfrac{5} \times 2}{12} \times 2} = {\dfrac10}24}}$ Now, we can subtract ${\dfrac{27}{24}} - \dfrac{10}{24}}$. $\dfrac{27}{24}$ $\dfrac{10}{24}$ $\dfrac{27}{24} - \dfrac{10}{24}$ $=\dfrac{{27}-10}}{24}$ $= \dfrac{17}{24}$ ${\dfrac{9}{8}} - \dfrac{5}{12}} = \dfrac{17}{24}$